Best available copv



1 No Model.)

H. P. KELLY.

OIBGUIT BREAKER.

Patented Mar. 16, 1897.

- or otherwise secured into UNITED STATES PATENT OFFICE.

HERBERT l. KELLY, OF PlIlLAD'iZLlIILd, PENNSYLVANIA.

CIRCUIT-BREAKER.

SPECHICATION forming part of Letters Patent No. 578,750, dated March 16,1897. Application filed p l 7, 1896. Serial No. 586,511. No model.)

To all whom it may concern:

Be itknown that I, HERBERT IAIXE KELLY, of the city and countyofPhiladelphia, Pennsylvania, have invented a new and Improved MagneticCircuit-Breaker; and I hereby declare the following to be a full, clear,and exact description of the same, reference being had to theaccompauyingdrawings, and to the letters of reference marked thereon.

My invention consists in the provision of a strip of metal or othersuitable conducting material in combination with a magnetic movable corearranged to operate as a hammer to break the said strip of metal,constructed and operated in the man nerhereinat'terdescri bed.

The object of the invention is to break electric currents topreventdestructive effect at any predetermined strength of current, alloperating in the manner and for the purpose hereinafter described.

In order to enable others to use and practice my invention, I willproceed to describe its construction and operation.

On reference to the accomp'myingdrawings, which form partof thisspecification, Figure 1 is a vertical section through center ofapparatus. Figs. 2 and 3 are side views of breakable metal strips. Fig.4 is a top view. Fig. 5, a bottom view; and Fig. 6 is a diagram of thecircuits.

Similar letters refer to which A is a magnetic yoke made of cast-ironprovided with lugs X X, which furnish means of support ofapparatusagainstswitchboard,&c. Said yoke has flat sides, as shown bydotted lines, Fig. 4.

C is a bushing of magnetic metal screwed cast-iron yoke A and providedwith a lining D' of a non-conducting and fire-resisting materiaL B isahollow core of magnetic metal free to move in a vertical direction. &idhollow core is lined With a non-conducting and fire-resisting tnbe D,the same material being used in the cross-bar D", secured firmly inplace to enable practical contact with lever E when operating in themanner and for the purpose hereinafter descri The non-conducting supportR is secured in position by four studs T, of non-magnetic metal, screwedinto magnetic yoke-cast-in g A,

similar parts, of

said non-conducting support being secured to same by ordinary screwsshown, and furnishes support. to said hollow core when in normalposition shown. 0 is one of the two terminal binding-clamps, into whichare secured the main wires carrying the current. The other of saidbinding-clamps is shown at L. N is an insulated conductor connectingsaid binding-clamp 0 with clamp P, which makes direct connection withand secures in place the lower end of the breakable metal strip Q, saidinsulated conductor) being secured into hole in said clamp P byset-screw1', which also serves to fasten said clamp P in place. 'lhesaidstripQcontinuesthe electric circuit to metal leverE to insulatedconnection M, from thence to coil J, from bottom of coil .l to insulatedconductor K, to above-mentioned terminal binding-clamp L, all operatingin the manner hereinafter described.

The end of lever E is pivoted in insulating-block F, and its free end iscurved downward so as to enter top of bushing C, said curved end beingprovided with a screw G to hold upper end of said metal breaking strip Qfirmly in place. Said lever E is provided with spiral spring II, securedin position shown in Fig. 1 by a metal pin at each end in a line closelyparallel across the pivoted point of said lever E. The effect is tocause little or no strain to pull lever in up- -ward direction from thenormal condition,

but exerts its full force as soon as lever is liberated and caused torise out of its normal position, as hereinafter more fully explained.

The ends of breakable strips Q are reinforced by being made thicker thancentral part and are provided with slots 1* W, which slots are providedto enable a clamping hold with bottom screw inPand top screw G. Themiddle portions of said breakable strips are fashioned as shown in Fig.3, being cut; from sheetmetal (or foil) at an angle. They are afterwardmade to have their edges conform to straight lines bybein g wrinkled, asshown in Fig. 2, forced apartis a tearing action, the straight orunwrinkled edge taking the firstst-rain, causing the metal first toseparate at that point. In attaching, the strip is secured to lever E,which can be lifted clear of obstructions for the eifect of which whenIOO that purpose, the said strip being first inserted in hole in centerof core. said core is lifted partly upward, exposing screw-head at P,under which lower end of strip is secured by means of lower slot W andcore is allowed to drop again into normal position.

Ordinary washers of non-conducting material of various thicknesses areplaced at point S to enable adjustment of distance between magnetic coreB and magnetic bushing C, for the purpose hereinafter explained.

The inner portion of coil J is provided with a metal tube-lining, inwhich the magnetic core B freely slides when operating, as hereinafterexplained.

The operation of the circuit-breaker is in this wise: \Vhen in seriescircuit with an electric-current generator and motors, lamps, or otherdevices, constituting a load, and the electric current exceeds apredetermined value fixed by adjusting thickness of washers S, insuringthe proper length of air-gap between magnetic core B and bushing C, themagnetic core B, which remains in position shown so long as current isnormal, then rises by its induced magnetism and flies upward withsuflicient force to operate as a hammer upon the lever E, causing themetal strip Q to break in the aforementioned middle portion, the twoparts separating, the lower remaining fixed, while the upper flies outof the center of bushing C and assumes the position shown by dottedlines, thus removing the said parts beyond arcing distance, after whicha similar strip Q can be inserted andthe operation repeated wheneveremergency requires the use of such safety appliance.

Next the.

What I claim, and desire to secure by Letters Patent, is

1. In a circuitebreaker, a breakable strip included in the circuit, andmechanical means controlled by the circuit for mechanically breaking thestrip without previously fusing it, substantially as described.

2. In a eircuit-breaker,the combination with an electromagnet, of aweakened conductingstrip included in the circuit of the magnet, asupport for said strip, aud electromagnetic means mechanically impingingon said support to break the strip, substantially as described.

3. In acircuit-breakcr,the combination with an electromagnet, of aweakened conductingstrip included in the circuit of the magnet, amovable support for one end of the strip, and a core electromagneticallyoperated to mechanically impinge upon the support and break the strip,substantially as described.

4. In a circuit-breaker, the combination with an electromagnet, of abreakable conductingstrip included in the circuit of the magnet, apivoted spring-controlled support for one end of the strip, and a coreelectromagnetically operated to impinge upon the support to break thestrip, substantially as described.

5. In a circuit-breaker, the combination of the magnet, the hollowc0re,the incombustible lining, the breakable strip mounted within thecore, and the spring-actuated support for said strip, substantially asdescribed.

HERBERT P. KELLY.

Witnesses:

EMILE. L. PUDRIAUX, GEO. L. Masox.

